This invention relates to a thermoplastic key cover or similar article of manufacture for attachment to a key of a piano or the like. More particularly, the present invention relates to such an article of manufacture made from marbleized thermoplastic material to simulate the grain of natural ivory with the marbleized thermoplastic material having coloristic properties and translucency to simulate a natural ivory key cover.
It is known in the art to adhere a rigid key cover plate of synthetic resin to the outer exposed ends of wooden, hammer-actuated linkages for contact by the fingers of a person playing the piano. The same type of key covers are attached to the keys of an organ or similar instruments. The cover plates are provided on new instruments and they may be replaced from time-to-time as required, for example, due to wear or damage due to abuse, failure of the adhesive and accidents. The synthetic resin must be accurately sized as to length, width and thickness before it is adhered to the surface of the key. After an existing key cover is removed, a coating of adhesive is applied to the surface of the key and/or cover to form a strong and essentially permanent bond between the cover plate and the key by positioning the cover on the key surface under moderate pressure.
It was a well accepted practice in the past to adhere cover plates fashioned from ivory to the keys of pianos and organs. Ivory not only provided well accepted aesthetic appearance but also was well suited because the exposed surface when contacted by the player's fingers was not affected by moisture and resisted wear, scratching and other mechanical abuse. Typically, an oversized cover fashioned from ivory was attached by glue to a key and then after the glue had set, the cover was reduced to the proper dimensions. However, the covers aged and yellowed to the point where it was necessary to remove and replace all the covers for the instrument. The replacement of a cover for one or more of the keys or even all the keys of an instrument is unduly expensive because of the skilled labor which is required and also because of the scarcity of ivory. After the ivory is sliced to the desired thickness, usually about 0.040 inch, the slabs of ivory are bleached to a uniform coloration. The bleached slabs of ivory typically have a translucency which necessitated the use of a white cover coat on the wooden surface of the keys to mask their natural wood-grain coloration. The white cover coat and translucent property of the ivory enhanced the aesthetic appearance of covered keys, which includes an added dimension of perceived depth.